Polarisation modulation dynamics of birefringent vertical cavity surface emitting lasers

An analysis of the direct current polarisation modulation response of birefringent single transverse mode vertical cavity surface emitting lasers is undertaken. Both small signal and large signal modulation responses are considered. Results show that out-of-phase responses in both orthogonal polarisations are obtained due to spatial hole burning effects for small modulation frequencies. Under large signal modulation a frequency doubling polarised output is obtained for frequencies smaller than 10 MHz. When the modulation frequency is increased the response is no longer dependent upon spatial hole burning, and in-phase responses in the two polarisations are obtained. The transition frequency between the out- and inphase responses is found to be about 100 MHz